Miniaturizing Ultrasonic System for Portable Health Care and Fitness

作者：Tang Hao Yen^*; Seo Dongjin; Singhal Utkarsh; Li Xi; Maharbiz Michel M; Alon Elad; Boser Bernhard E

来源：IEEE Transactions on Biomedical Circuits and Systems, 2015, 9(6): 767-776.

DOI：10.1109/TBCAS.2015.2508439

• Terms Fitness tracking
• high-voltage generation
• in-vivo 2-D ultrasound
• ultrasonic imager

We present a miniaturized portable ultrasonic imager that uses a custom ASIC and a piezoelectric transducer array to transmit and capture 2-D sonographs. The ASIC, fabricated in 0.18 mu m 32 V CMOS process, contains 7 identical channels, each with high-voltage level-shifters, high-voltage DC-DC converters, digital TX beamformer, and RX front-end. The chip is powered by a single 1.8 V supply and generates 5 V and 32 V internally using on-chip charge pumps with an efficiency of 33% to provide 32 V pulses for driving a bulk piezoelectric transducer array. The assembled prototype can operate up to 40 MHz, with beam former delay resolution of 5 ns, and has a measured sensitivity of 225 nV/Pa, minimum detectable signal of 622 Pa assuming 12 dB SNR (4 sigma larger than the noise level), and data acquisition time of 21.3 ms. The system can image human tissue as deep as 5 cm while consuming less than 16.5 mu J per pulse-echo measurement. The high energy efficiency of the imager can enable a number of consumer applications.

• 出版日期2015-12